Question

struct G{

    G&operator()(const int**a)
    {
       v<<a;
       std::copy(v.begin(),v.end(),std::ostream_iterator<int>(std::cout, " "));
       return *this;
    }
    friend std::vector<int>&operator<<(std::vector<int>&v,const int** n);
    std::vector<int>v;
};

std::vector<int>&operator<<(std::vector<int>&v,const int** n)
{
    v.insert(v.begin(),*n,*n+sizeof(*n)/sizeof(*n[0]));
    return v;
}

/// use it
G g; 
int v[8]={1,2,3,4,5,6,5,4};
g(&v);

I have two questions,
1. The above code returns with error cannot convert parameter 1 from 'int (*)[8]' to 'const int **'
2. I would like to pass in g as g({1,2,3,4,5,6,5,4}) instead of g(&v). But I don’t know how to do that and always wonder if g will accept it.
Thank you.

Answer 1

1. &v is giving you the address of the array, when you want the address of a pointer. Try doing const int* x = v then g(&x).

2. In C++0x, you can do this:

   G& operator()(std::initializer_list<const int>);
   g({1,2,3,4,5,6,5,4});